Home electric troubleshooting

[masraum]

Originally Posted by Gogar

And while you're there get one of these. Really makes things easier when you're trying to find the run that's hot and the runs that are not!

I've got these






(plus at least one other, maybe 2)

it was free from an old job.


I ended up rewiring that one outlet back the way that it had been (on a pigtail) because there were 2 more outlets that were supposed to have been on that circuit that had never been connected. So I had to add a third wire to that box to get power to the 2 other outlets. I'll have a little more rewiring to do in the future, but nothing too crazy. I'll add a GFCI to the first outlet, and then add in the last outlet.

Plus I'll be putting the breaker finder to use to figure out where a couple of wires are going.

[1990C4S]

Make sure you test your meters/indictors on a live circuit and get a proper indication of voltage before you trust the device, especially the Fluke probe.

[masraum]

Originally Posted by 1990C4S

Make sure you test your meters/indictors on a live circuit and get a proper indication of voltage before you trust the device, especially the Fluke probe.

Good call. Test a real positive before relying on them for possible positive/negative.

Maybe I should have checked this out for tips and tricks.

[E Sully]

Just a couple of notes here. I was a Union electrician in NYC, and we were taught a little different than electricians doing residential in the suburbs.
We never used 14awg, 12awg was the minimum branch circuit wire even on 15amp circuits. Back in the day 14awg was allowed in the suburbs, but now kitchens are required to have a 12awg minimum.
Most suburban homes had outlets "back-wired". Meaning instead of putting wires under the screws, they were pushed into the holes in the back of the outlet where an internal spring clip held them in. This was quicker, but not as solid as under the screw. Of course you also couldn't push the heavier 12awg wire into the back-wire hole in 15amp switches and receptacles.
Another thing is devices were wired with this method in single family homes.

This carried the branch circuit through the box to the next on the same circuit. In the city we were required to wire them this way, or pig tailed.

This was important. If was to maintain power to the rest of the circuit if one device was removed, or if a device went bad. You wouldn't want a computer down the line to go out if something was wrong with one of the devices ahead of it. I have replaced many an outlet for friends and family where the circuit went out from a failed back wire connection. Yes, it can take up more space, but boxes are sized for the number of conductors and an appropriate size box needs to be used.
As for the breaker, I would have to think it is a GFCI due to being in the kitchen near the sink. Does it look similar to this one?

If so, then the black and white neutral from the circuit wire need to attach to the breaker with the white tail from the breaker going to the neutral bar. If the white neutral from the circuit went directly to the neutral bar the breaker will not work.
One example.
https://pdf.lowes.com/productdocuments/08c7a5b9-3941-400f-a9e4-62c39b21b942/60986416.pdf
As for billybek in post #12, one main reason to cut the tab between the 2 screws was that half the outlet would be continuous power, and the other half would be wire to a wall switch for a lamp to plug in. Back in the day that was how bedrooms were wired when there were no recessed ceiling lights or fans.

[john70t]

Originally Posted by E Sully

This carried the branch circuit through the box to the next on the same circuit. In the city we were required to wire them this way, or pig tailed.

That actually seems to make sense.

The only downside would be having 3x heavy 12gauge wires crammed into one twist-connector. The wires would have to be pre-twisted with a tool I would think before the cap is installed. And there would have to be sufficient wire hanging out and crammed back in to bridge from several different box knockout entries.

Another potential problem might be one of the two outlets is independent and wall-switched for a floor lamp or other. I've seen that a few times. Connecting those might cause havoc.

[Zeke]

Originally Posted by john70t

That actually seems to make sense.

The only downside would be having 3x heavy 12gauge wires crammed into one twist-connector. The wires would have to be pre-twisted with a tool I would think before the cap is installed. And there would have to be sufficient wire hanging out and crammed back in to bridge from several different box knockout entries.

Another potential problem might be one of the two outlets is independent and wall-switched for a floor lamp or other. I've seen that a few times. Connecting those might cause havoc.

RE: first sentence. 2 cables coming in thru 1 KO or 2, up to you, and they are stripped of the outer sheath at the entry. Inside the blacks, whites and grounds are individual wires twisted (should be) and wire nutted. You push the 3 assemblies, ground bundle first to the back of the box. You actually mash the grounds with the butt of your hammer and then push the blacks and whites in respectively. The 3 wires connected to the device are folded in an accordion style and the device pushed in last. There is plenty of room for a duplex receptacle. GFCI's can get tight and you need to make up the wires neatly.

Sentence 2: If you have 3 cables coming in and one is for switched power, a standard box will become overfilled according to the wire fill charts. Maybe 14 ga will work, 12 requires a deep box or a 4 x 4 box and mud ring. These days I will use a 2 gang box and add a receptacle.

[masraum]

Originally Posted by E Sully

Just a couple of notes here. I was a Union electrician in NYC, and we were taught a little different than electricians doing residential in the suburbs.
We never used 14awg, 12awg was the minimum branch circuit wire even on 15amp circuits. Back in the day 14awg was allowed in the suburbs, but now kitchens are required to have a 12awg minimum.
Most suburban homes had outlets "back-wired". Meaning instead of putting wires under the screws, they were pushed into the holes in the back of the outlet where an internal spring clip held them in. This was quicker, but not as solid as under the screw. Of course you also couldn't push the heavier 12awg wire into the back-wire hole in 15amp switches and receptacles.

I've run into the whole back wire thing and thought that it was pretty cool, but then read that it's not as good as using the screw terminals on the side of the receptacle.

I think 12AWG is code now for 15A circuits over a certain length.

Another thing is devices were wired with this method in single family homes.

This carried the branch circuit through the box to the next on the same circuit. In the city we were required to wire them this way, or pig tailed.

This was important. If was to maintain power to the rest of the circuit if one device was removed, or if a device went bad. You wouldn't want a computer down the line to go out if something was wrong with one of the devices ahead of it. I have replaced many an outlet for friends and family where the circuit went out from a failed back wire connection. Yes, it can take up more space, but boxes are sized for the number of conductors and an appropriate size box needs to be used.

Why do both of your examples ignore the ground wire? Is that just to make the diagram cleaner?

As for the breaker, I would have to think it is a GFCI due to being in the kitchen near the sink. Does it look similar to this one?

If so, then the black and white neutral from the circuit wire need to attach to the breaker with the white tail from the breaker going to the neutral bar. If the white neutral from the circuit went directly to the neutral bar the breaker will not work.

Nope, not a GFCI breaker, and technically, none of the outlets on this circuit are near the sink. It's a 100 year old home that was rewired around 1990 so it's fairly modern. It's all romex and copper. I added all of the GFCI outlets that are in the house. The guys that did the electrical said that the box on our house is no longer made/available, but either they had or a few breakers are still available.

[masraum]

Originally Posted by john70t

That actually seems to make sense.

The only downside would be having 3x heavy 12gauge wires crammed into one twist-connector. The wires would have to be pre-twisted with a tool I would think before the cap is installed. And there would have to be sufficient wire hanging out and crammed back in to bridge from several different box knockout entries.

Another potential problem might be one of the two outlets is independent and wall-switched for a floor lamp or other. I've seen that a few times. Connecting those might cause havoc.

twisting 3x 12awg under a nut is a beyotch for sure, but what's even worse is trying to get all of the 12awg wiring shoved back into a box neatly.

[masraum]

Originally Posted by Zeke

RE: first sentence. 2 cables coming in thru 1 KO or 2, up to you, and they are stripped of the outer sheath at the entry. Inside the blacks, whites and grounds are individual wires twisted (should be) and wire nutted. You push the 3 assemblies, ground bundle first to the back of the box. You actually mash the grounds with the butt of your hammer and then push the blacks and whites in respectively. The 3 wires connected to the device are folded in an accordion style and the device pushed in last. There is plenty of room for a duplex receptacle. GFCI's can get tight and you need to make up the wires neatly.

Sentence 2: If you have 3 cables coming in and one is for switched power, a standard box will become overfilled according to the wire fill charts. Maybe 14 ga will work, 12 requires a deep box or a 4 x 4 box and mud ring. These days I will use a 2 gang box and add a receptacle.

Cool, great info, sir!

[john70t]

Originally Posted by masraum

twisting 3x 12awg under a nut is a beyotch for sure,

I've used worn out pliers and spin them into a cone but it's something worth buying a tool for and the right connectors.
The retention spring isn't made for that.
There's no greater fun than sparky walls.
.

[masraum]

Originally Posted by john70t

I've used worn out pliers and spin them into a cone but it's something worth buying a tool for and the right connectors.
The retention spring isn't made for that.
There's no greater fun than sparky walls.
.

Our first home that we lived in for ~17 years was built in '67 and had aluminum wiring. I'm no stranger to sparky switches and outlets and switches. WHen we moved in, I replaced all of the outlets with co/alr and bought some "no alox".

I've got lineman's pliers.

[E Sully]

The NEC does not directly address the number of NM cables in a ko, just stating the wire must be secured. To make sure it is done right you have to check with the manufacturer of the box or connector to see how they rate it. Take this for example, https://www.aifittings.com/media/spec-sheets/NMR840.pdf
• 3/8" trade size fits 1/2" knockout
• For NM and flexible cord:
(1) 14/2 flat to (1) 10/3 round cables
(2) 14/2 to (2) 12/2 flat cables
(1) 14/3 to (1) 10/3 flat cable
(2) 14/3 to (2) 12/3 flat cable
(1) 14/3 to (1) 10/3 round cable
It can be fun to tail the ground wire to each of the devices. In the city this was not an issue since the conduit and boxes are metallic and usually provided the ground. 12awg can be challenging for the homeowner. The minimum length of wire in a box is 6" so correct box sizing and careful dressing of wires is important. I frequently had to make multiple 12awg splices up to 5 wires. I mainly dealt with metal boxes and raised covers, with plastic boxes it can be tougher. The 2-4 gang switch boxes in my living room was fun.
The main thing the inspector looked for when I built my addition was that fire proof caulking was used at the holes were the wire passed through.

[john70t]

Originally Posted by E Sully

The main thing the inspector looked for when I built my addition was that fire proof caulking was used at the holes were the wire passed through.

Yah. City housing inspectors also wanted rockwool stuffing with red 3M foam/caulk behind the cabinet for all pipe-wall penetrations. This prevents the stove pipe effect feeding any fire with oxygen from below.

[Zeke]

@E Sully, yeah but in general 2 cables to a clamp listed for such, and 2 under a staple. Do that and you'll have no trouble. There are 3/4" cable clamps that are listed for 3 12 ga or 4 14 ga. Not a code hound but IDT many inspectors are going to be happy with 5 of anything entering a box thru a single hole.

[E Sully]

I agree with you Zeke. I follow the same 2 per clamp, metal staple as you.
But there are other options for multiple cables.